wso2api: Fetch API endpoint url from /store API and return as an attribute of the construct

## Problem being solved
For integration tests it's good to have the actual URL of the provisioned API, especially for testing PR environments, so it's good to have this endpoint url being returned.

## Proposal
Fetch API Endpoint URL from /store.

Note: We disabled this feature due to some errors with some WSO2 instances in regard to permissioning to access this endpoint, so you can see some commented out portions of the code as in https://github.com/flaviostutz/cdk-practical-constructs/pull/62